Accepting USDT Payments in Laravel: A PHP Integration Guide

Service Class

// app/Services/PaychainlyService.php
class PaychainlyService {
  public function createPaymentLink(float $amount, string $description, array $metadata = []): array {
    $response = Http::withHeaders(['x-api-key' => config('services.paychainly.key')])
      ->post('https://api.paychainly.com/api/v1/payment-links', compact('amount', 'description', 'metadata'));
    return $response->json('data');
  }

  public function verifySignature(string $payload, string $signature): bool {
    $expected = 'sha256=' . hash_hmac('sha256', $payload, config('services.paychainly.webhook_secret'));
    return hash_equals($expected, $signature);
  }
}

Webhook Controller

class PaychainlyWebhookController extends Controller {
  public function handle(Request $request, PaychainlyService $paychainly) {
    $payload = $request->getContent();
    $sig = $request->header('X-Paychainly-Signature');

    abort_unless($paychainly->verifySignature($payload, $sig), 401);

    $event = $request->json()->all();

    ProcessPaymentJob::dispatchIf(
      !ProcessedPayment::where('tx_hash', $event['txHash'])->exists(),
      $event
    );

    return response()->json(['status' => 'ok']);
  }
}

Queue Job

class ProcessPaymentJob implements ShouldQueue {
  use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

  public function handle() {
    ProcessedPayment::firstOrCreate(
      ['tx_hash' => $this->event['txHash']],
      ['user_id' => $this->event['userId'], 'amount' => $this->event['amount']]
    );
    // Credit user, send email, etc.
  }
}

Config

// config/services.php
'paychainly' => [
  'key' => env('PAYCHAINLY_API_KEY'),
  'webhook_secret' => env('PAYCHAINLY_WEBHOOK_SECRET'),
],

Route

Route::post('/webhooks/paychainly', [PaychainlyWebhookController::class, 'handle'])
  ->withoutMiddleware(['auth', 'throttle']); // bypass auth but keep signature check